How to approach

#1

please explain sir cant get it??

#2

hello @ahujaxrhythm
The algorithm for this problem is simple
a) first u need to read the dimension of the matrix say (M XN)
b) after that u need to read the matrix
c) and then for every even column(column number starts from 0 ) print top to bottom and for every odd column print bottom to top.

#include<iostream>
using namespace std;
int main() {
	int M,N;
	cin>>M>>N;   //reading dimesnions
	int arr[100][100];
	for(int i=0;i<M;i++){   //reading matrix
		for(int j=0;j<N;j++){
			cin>>arr[i][j];
		}
	} 
	for(int i=0;i<N;i++){   // itearting columwise
		if(i%2==0){     // for even column
			for(int j=0;j<M;j++){   //printing top to bottom
				cout<<arr[j][i]<<", ";
			}
		}
		else{    //for odd column
			for(int j=M-1;j>=0;j--){ //printing bottom to top
				cout<<arr[j][i]<<", ";
			}
		}
	}
	cout<<"END";
	return 0;
}